Problem: $ { \left[\begin{array}{rr}{0} & {0} \\ {3} & {4} \\ {3} & {4}\end{array}\right]-\left[\begin{array}{rr}{1} & {4} \\ {-1} & {1} \\ {-2} & {2}\end{array}\right] = {?} } $
Answer: To find the difference of two matrices, subtract the corresponding items between each matrix. ${\left[\begin{array}{rr}{0}-{1} & {0}-{4} \\ {3}-{-1} & {4}-{1} \\ {3}-{-2} & {4}-{2}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{rr}{-1} & {-4} \\ {4} & {3} \\ {5} & {2}\end{array}\right]}$